I also have heating problems.
Beginning at least a year ago, sometime would get no heat regardless of the position of the temperature slider - or sometimes 100% heat, and I'd have to turn on and off the fan to maintain a comfortable temperature. Sometimes it would go back to normal operation where I could control the temperature.

The AC needed a recharge shortly after I bought the van used so I just pulled the fuse from the AC clutch because in defrost position the AC comes on whether the temp is on hot or cold, summer or winter. I guess it was designed that way to dehumidify the defroster air.

Sometimes just driving with nothing on (no heat or AC), I hear the servo motor running?? I expect this is indicative of problems.

Now all the heater fan speed controls do not work, other than full - no problem, I understand the resistors go.

Someone also indicated another problem I used to have last winter... I had to turn the fan on high to get the door / deflector to "Thump" closed, then I would have heat until I turned off the vehicle. Now however I can't get it to "thump" closed anymore so I have not heat directed into the cabin.
The controls to direct air to the face, feet and defroster vents work - just no heat.

I ran the diagnostic today (by holding the Wiper and the Wash buttons at the same time). First time I ran it I didn't turn on the fan which I later read I should do. The first results ended in the indicator lights cycling between the Wiper Light flashing 1 time, and the Intermittent Wiper light flashing 4 times. When done the system indicated an error by flashing both these lights when I turned on the car and this condition would not clear until I re-ran the test as below.
After further reading, I later re-ran the test as suggested with the FAN on FULL, the TEMP on COLD and the Selector on FACE. It Ran now with only the Wiper Light giving me a single flash and kept repeating this. This time when I pressed the wiper button, it successfully terminated the diagnostic test with no lights left on.
* Anyone know what the single blink means? *
Someone else posted in another thread a similar thing (F-150 Hauler) with a broken nipple connected to an actuator or something like that...
I do not suspect a heater core, a thermistat or insufficient coolant.
I suspect a mechanical or electrical issue in the dash.
Anyone have any suggestions?
I'm not looking for the Fix-All. I'm just looking for a quick fix for the winter so I can defrost the front window and not freeze on long drives.
Thanks in advance.

 

Code 1 is: actuator did not reach defrost position. but you already knew that lol

the diagnistic test for code 1 is.
http://i54.tinypic.com/112bfdf.jpg

 

T stat... and or possible heater core is clog or blocked....

 

Thanks for the replies!!
Hemi, thanks for the info and the Picture for the diags. I will get to checking voltages... Any more info from that source? I'm not clear about that code result "Actuator did not reach defrost position". Air is being redirected out the defroster. If I select "Feet", it goes to feet, "Face", it goes to face??
USMarine, Thanks also - I don't suspect these because of the ALL ON or ALL OFF symptoms prior to the current state of ALL OFF.
I'm suspecting either aged, non-functioning controls, a bad linkage from actuator to flap... or a combo of the two.
Where as it used to work when I'd hear the "Thump" of a Flap closing and then heat would be direct inside, I suspect a linkage problem.
When it would come on 100% hot or 100% cold with no control of the temp, I don't recall the Flap malfunction then. I suspect that was the control or bad ground or something like that.
The flap not closing thing happened after the lack of temp control.
Did I mention that occasionally, the dash gauges (speedo, RPM,) intermittently do not function. I'll start it and No gauges. A couple days later they come back.
Just looking for a place to start looking when I pull the dash. I do have a manual but any images, charts, figures, ... would be most helpful.
Thanks again!!!

 

Finally got back to it. Yup, air pocket or something. The van was due for a cooling system flush and that took care of it.

Heat in abundance. Thanks for all your help.

 

I have a problem with my 98 Caravan that is similar and I'm wondering if it's the same thing. One day it was working and the next day it wasn't. Right now it doesn't matter where I set the temp, it feels like A/C air. And up until this happened I was hearing thumps in my dash whenever I would start the van or change the control from panel to defrost , etc. I have also been experiencing the intermittent non-start problem that I seem to be able to solve by moving the battery cable-either hot or ground. The non-start issue seemd to go away for a l ong time, then rear its ugly head when it's really cold or raining or I'm really in a hurry. But right now I'm worried about the heat. Should I go ahead and change the thermostat?

 

Mitch54

I was able to repair my brother's... in the DIY section there is a link for Calibration of the doors. I have the email'd copy on my pc, but I can not find the link. If you can not find it send me an email, and i will copy and paste it for you...
Usmarine0905@aol.com

 

That worked!!! Thanks. I ran the diagnostics and everything worked right. I tried running the diagnostice before, but I think I may have pushed the wrong button.

 

@ mitch54 ... glad I could help...

 

i have replaced the radiator the water pump flushed out the heater core the heat come on but doesnt stay hot. my rear wimdow defroster doesnt work but i cant find the location to replace it. i need location or diagram if this doesnt work what do i do next. please someone help i am a mother in the winter with a vehicle with no heat please.